The present invention relates to a fixing oil coating apparatus and more specifically to a fixing oil coating apparatus to coat oil on an outer circumferential surface of a fixing roller in order to fix a toner image on a supporting material such as a recording sheet and the like.
Conventionally, as an oil coating roller employed in the fixing oil coating apparatus, as shown in FIG. 7, there has been disclosed an apparatus having a structure in that a hollow pipe-shaped metal core 101 is wound with felt cloth 100; in the inner hollow portion of the above-mentioned core 101, oil 102 is stored and the oil is supplied to the above-mentioned felt cloth through a plurality of holes 103 formed by penetrating the circumferential wall of the above-mentioned core 101 (refer to Japanese Utility Model Publication Open to Public Inspection 59-73762, etc.).
Further, in FIG. 7, the reference numeral 104 shows a rotation axis of an oil coating roller and the reference numeral 105 shows a fixing roller on which the oil is coated by the above-mentioned oil coating roller.
However, in the above-mentioned conventional oil coating roller, a problem has been caused in that when the toner adheres to a felt cloth 100 as an oil coating member, it is readily clogged and the oil cannot be consistently coated on the fixing roller 105 for a long time of period.
Furthermore, in the construction in that the oil 102 stored in the hollow portion of the core 101 is supplied to the felt cloth 100 through the holes 103, there has been a possibility such that it is difficult to supply uniformly the oil to the felt cloth 100 and the oil is not uniformly coated on the fixing roller 105.
In the coating roller employing a ceramic member, there has been a problem in that because the oil is supplied to all the region in the axial direction of the ceramic member, oil drips are caused in the portion (out of the maximum sheet width) where no sheet is passed.
Namely, in the oil coating roller, in the region (sheet passing portion) where a sheet is passed, oil consumption and oil coating are repeated. However, in the region (no sheet passing portion) where a sheet is not passed, the oil coating is repeated without consuming the oil and the oil is accumulated. When the oil accumulated state is left for many hours, the oil accumulated in the no sheet passing region moves to the sheet passing portion. As a result, when started again, the oil drips are caused in the sheet passing portion and the sheet is liable to be stained by oil spots.